Environmental and occupational exposure among cancer patients in Mato Grosso, Brazil.

OBJECTIVE: To estimate the prevalence of occupational and environmental exposure according to sociodemographic factors in cancer patients treated at reference hospitals in the state of Mato Grosso, Brazil. METHODS: This is a cross-sectional study on cancer patients aged 18 years or older. The prevalence of exposure to pesticides, asbestos, lead, heavy metals, formaldehyde, benzene, exposure to industrial dust, and handling of other chemical substances were calculated according to sex, age group, and level of education. RESULTS: A total of 1,012 patients were interviewed (55.0% women, 45.6% aged 60 years or older, and 56.8% had less than five years of formal education). Pesticides (22.8%), industrial dust (10.7%), and benzene (10.1%) were the most frequent exposures. Occupational and environmental exposure was higher in men for all evaluated exposures, except for formaldehyde, which was higher in women. Exposure to pesticides, industrial dust, benzene, asbestos, and heavy metals increased with age and were more frequent among those with lower level of education. CONCLUSION: Approximately one in five cancer patients treated at reference hospitals in Mato Grosso reported having been exposed to pesticides, and one in ten were exposed to industrial dust and benzene, with greater exposure among men, older individuals, and those with lower level of education.

Maternal exposure to benzene and toluene and preterm birth. A longitudinal study

ABSTRACT BACKGROUND: Exposure to air pollutants has several effects on human health, including during pregnancy. OBJECTIVE: To identify whether exposure to benzene and toluene among pregnant women contributes to preterm delivery. DESIGN AND SETTING: Longitudinal study using data on newborns from mothers living in São José dos Campos (SP) in 2016, who had been exposed to benzene and toluene. METHODS: A logistic regression model with three hierarchical levels was constructed using maternal variables relating to newborns, and using benzene and toluene concentrations in quartiles. Occurrences of cesarean births, twins or malformations were excluded. Maternal exposure windows of 5, 10, 15, 30, 60 and 90 days prior to delivery were considered. RESULTS: Out of the 9,562 live births, 3,671 newborns were included and 343 newborns were born at less than 37 weeks of gestation (9.3%). The average birth weight was 3,167.2 g. Exposure to benzene and toluene was significantly associated (P = 0.04) with preterm delivery in the five-day window. There was no association in any of the other exposure windows. CONCLUSIONS: It was possible to identify that maternal exposure to benzene and toluene has an acute effect on preterm delivery.

Environmental exposure to benzene: evaluation of urinary S-PMA and polymorphism (CYP2E1-1293G>C and NQO1 609C>T) in Campos Elíseos residents, Duque de Caxias, Rio de Janeiro State, Brazil.

Benzene is one of the most important substances for assessment, due to its significant use, the environmental contamination resulting from its emission and the effects on human health. It is classified by the International Agency for Research on Cancer (IARC) as a known carcinogen to humans (group 1) and associated with the development of leukemia. In general, the population is exposed to this substance by inhaling contaminated air, which varies according to the location and intensity of its potential sources. The petrochemical industry is one of the most important sources of this compound. The municipality of Duque de Caxias, specifically the Campos Elíseos district, in Rio de Janeiro State, Brazil, houses the Industrial Complex of Campos Elíseos (PICE), a grouping of over 25 industries, which includes the second largest oil refinery in Brazil. Environmental contamination from the PICE has been recognized, but there is a lack of studies concerning its impact on the health of the surrounding population. S-phenylmercapturic acid (S-PMA) concentrations ranging from 0.80 to 8.01µg.g-1 creatinine were observed in the local population, apparently related to hematological changes also observed in exposed population. The quantifiable presence of urinary S-PMA from the benzene metabolism is associated with the fact that 60% of the participants present specific hematological changes, which may be due to the environmental benzene exposure. The allele and genotype frequencies of the CYP2E1 and NQO1 enzymes observed in the study population were similar to those reported in other studies. The presence of the variant allele in the NQO1 genotype may be a risk factor for the observed hematological changes.

Maternal exposure to benzene and toluene and preterm birth. A longitudinal study.

BACKGROUND: Exposure to air pollutants has several effects on human health, including during pregnancy. OBJECTIVE: To identify whether exposure to benzene and toluene among pregnant women contributes to preterm delivery. DESIGN AND SETTING: Longitudinal study using data on newborns from mothers living in São José dos Campos (SP) in 2016, who had been exposed to benzene and toluene. METHODS: A logistic regression model with three hierarchical levels was constructed using maternal variables relating to newborns, and using benzene and toluene concentrations in quartiles. Occurrences of cesarean births, twins or malformations were excluded. Maternal exposure windows of 5, 10, 15, 30, 60 and 90 days prior to delivery were considered. RESULTS: Out of the 9,562 live births, 3,671 newborns were included and 343 newborns were born at less than 37 weeks of gestation (9.3%). The average birth weight was 3,167.2 g. Exposure to benzene and toluene was significantly associated (P = 0.04) with preterm delivery in the five-day window. There was no association in any of the other exposure windows. CONCLUSIONS: It was possible to identify that maternal exposure to benzene and toluene has an acute effect on preterm delivery.

Environmental exposure to benzene: evaluation of urinary S-PMmorphism (CYP2E1-129A and poly3G>C and NQO1 609C> T) in Campos Elíseos residents, Duque de Caxias, Rio de Janeiro State, Brazil / Exposição ambiental ao benzeno: avaliação do S-PMA urinário e de polimorfismos (CYP2E1-1293G>C e NQO1 609C> T) em residentes de Campos Elíseos, Duque de Caxias, Rio de Janeiro, Brasil / Exposición ambiental al benceno: análisis del S-PMA en la orina y polimorfismo (CYP2E1-1293G>C y NQO1 609C> T) en residentes de Campos Elíseos, Duque de Caxias, Río de Janeiro, Brasil

Benzene is one of the most important substances for assessment, due to its significant use, the environmental contamination resulting from its emission and the effects on human health. It is classified by the International Agency for Research on Cancer (IARC) as a known carcinogen to humans (group 1) and associated with the development of leukemia. In general, the population is exposed to this substance by inhaling contaminated air, which varies according to the location and intensity of its potential sources. The petrochemical industry is one of the most important sources of this compound. The municipality of Duque de Caxias, specifically the Campos Elíseos district, in Rio de Janeiro State, Brazil, houses the Industrial Complex of Campos Elíseos (PICE), a grouping of over 25 industries, which includes the second largest oil refinery in Brazil. Environmental contamination from the PICE has been recognized, but there is a lack of studies concerning its impact on the health of the surrounding population. S-phenylmercapturic acid (S-PMA) concentrations ranging from 0.80 to 8.01μg.g-1 creatinine were observed in the local population, apparently related to hematological changes also observed in exposed population. The quantifiable presence of urinary S-PMA from the benzene metabolism is associated with the fact that 60% of the participants present specific hematological changes, which may be due to the environmental benzene exposure. The allele and genotype frequencies of the CYP2E1 and NQO1 enzymes observed in the study population were similar to those reported in other studies. The presence of the variant allele in the NQO1 genotype may be a risk factor for the observed hematological changes.

O benzeno é uma das substâncias mais importantes para a biomonitorização, em função do uso disseminado, da contaminação ambiental que resulta da emissão e dos efeitos sobre a saúde humana. O benzeno é classificado pela Agência Internacional de Pesquisa em Câncer (IARC) como carcinógeno conhecido em seres humanos (grupo 1) e está associado ao desenvolvimento de leucemias. Em geral, a população fica exposta a essa substância através da inalação do ar contaminado, que varia de acordo com a localização e a intensidade das fontes potenciais. A indústria petroquímica é uma das fontes mais importantes desse composto. O Município de Duque de Caxias, especificamente o Distrito de Campos Elíseos, no Estado do Rio de Janeiro, Brasil, é sede do Polo Industrial de Campos Elíseos (PICE), um conjunto de mais de 25 indústrias que inclui a segunda maior refinaria de petróleo no Brasil. A contaminação ambiental produzida pelo PICE já é conhecida, mas faltam estudos sobre o impacto na saúde da população local. Foram observadas concentrações de ácido S-fenilmercaptúrico (S-PMA) entre 0,80 e 8,01μg.g-1 creatinina na população local, aparentemente implicadas nas alterações hematológicas também observadas na população exposta. A presença quantificável do S-PMA urinário do metabolismo do benzeno está associada ao fato de 60% dos participantes apresentarem alterações hematológicas específicas, o que pode ser devido à exposição ambiental ao benzeno. As frequências alélicas e genotípicas das enzimas CYP2E1 e NQO1, observadas na população do estudo, foram semelhantes àquelas relatadas em outros estudos. A presença da variante alélica do genótipo NQO1 pode ser um fator de risco para as alterações hematológicas observadas.

El benceno es una de las sustancias más importantes susceptibles de estudio, debido a su uso significativo, la contaminación ambiental resultante de sus emisiones y sus efectos sobre la salud humana. Está clasificado por el Centro Internacional de Investigaciones sobre el Cáncer (IARC) como un conocido carcinógeno para los humanos (grupo 1) y está asociado con el desarrollo de leucemias. En general, la población está expuesta a esta sustancia por inhalación de aire contaminado, que varía según el lugar y la intensidad de las emisiones. La industria petroquímica es un de las fuentes emisoras más importantes de este compuesto. La municipalidad de Duque de Caxias, específicamente el distrito de Campos Elíseos, en Río de Janeiro, Brasil, alberga el Complejo Industrial de Campos Elíseos (PICE), un conglomerado de más de 25 industrias, que incluye la segunda mayor refinería de petróleo en Brasil. La contaminación ambiental procedente del PICE ya ha sido reconocida, pero es notable la falta de estudios respecto a su impacto en la salud de la población circundante. Se observaron en la población local concentraciones de ácido s-fenilmercaptúrico (SPMA por sus siglas en inglés) que oscilan entre los 0,80 a 8,01μg.g-1 creatinina, aparentemente relacionadas con cambios hematológicos también hallados en la población expuesta. La presencia cuantificable de SPMA en la orina, procedente del metabolismo del benceno, está asociada con el hecho de que un 60% de los participantes presenta cambios específicos hematológicos, los cuales tal vez se deben a la exposición ambiental al benceno. Las frecuencias alélicas y genotípicas del CYP2E1 y enzimas NQO1 observadas en el estudio fueron similares a las reportadas en otros estudios. La presencia de la variante alélica en el genotipo NQO1 podría ser un factor de riesgo para los cambios hematológicos observados.

Polimorfismos metabólicos e alterações clínicas e laboratoriais relacionadas à exposição ao benzeno em trabalhadores de postos de combustíveis da cidade do Rio de Janeiro / Metabolic polymorphisms and clinical and laboratory changes related to exposure to benzene in city gas station workers in Rio de Janeiro

A exposição ao benzeno representa um sério problema de Saúde Pública, apesar das medidas de limitação e controle empregadas nas últimas décadas. Os trabalhadores depostos de combustíveis representam uma categoria que vem sendo continuamente exposta a substâncias presentes na gasolina, dentre as quais o benzeno, capaz de causar um conjunto de sinais e sintomas denominado benzenismo, cujo diagnóstico é epidemiológico e clínico baseado na busca de alterações clínicas, principalmente hematológicas. Este estudo avaliou alterações clínicas relacionadas ao benzenismo e seis polimorfismos de genes de metabolização do benzeno em trabalhadores de postos de combustíveis do município do Rio de Janeiro. (...) A população foi categorizada em dois grupos, de acordo com a presença das alterações clínicas, principalmente sinais hematológicos. A maioria dos trabalhadores, 63,2 por cento, apresentou alterações clínicas compatíveis com o benzenismo. Estes trabalhadores mostraram diminuição na contagem de células sanguíneas, com diferença significativa para os valores de neutrófilos e MCV (indicativo de macrocitose). Este grupo mostrou maior frequência de sintomas como cefaléia, infecções repetidas, câimbras musculares,formigamentos, sonolência, tontura e perda de peso, embora nem todos com diferença significativa. (...) A mostraram freqüências mais altas dos alelos relacionados ao risco entre os trabalhadores com alterações clínicas. Foi observada uma associação entre as alterações clínicas relacionadas ao benzenismo e o genótipo nulo da GSTM1 e também com maior número de alelos relacionados ao risco (em conjunto). Entretanto, estudos baseados em maior tamanho amostral, são necessários para confirmação destes achados. Variações em genes de metabolização do benzeno devem ser consideradas nos estudos de avaliação de risco de trabalhadores expostos, por serem capazes de modificar a toxicidade do composto.

Exposure to benzene, especially in developing countries like Brazil, continues to represent a serious Public Health problem despite limiting exposure measures used inrecent decades. The gas station workers represent a category that has been continuously exposed to substances present in gasoline, especially benzene, which can cause a number of signs and symptoms which characterize the benzene poisoning. The diagnosis of benzene poisoning is epidemiological and clinical, based on the search for clinical findings, mainly hematologic. This study evaluated clinical alterations related to benzene poisoning and six polymorphisms of benzene metabolism genes in gas station workers in the city of Rio de Janeiro. (...) metabolic polymorphisms of benzene were analyzed in this study. The population was categorized into two groups according to the presence of clinical changes, hematological signs mainly. Most workers presented clinical findings, 63.2 percent. These workers showed a decrease in blood cells count, with a significant difference to the values of neutrophils and Mean Corpuscular Volume (MCV) (indicative of macrocytosis). This group showed a higher frequency of symptoms such as headache, repeated infections, muscle cramps, tingling, drowsiness, dizziness and weight loss, although not all with significant differences. (...) A genotypes. Moreover, an association was found between alterations related to benzene poisoning and GSTM1 null and the highest number of alleles related to risk. Further studies of larger samples are needed to confirm these findings. Variations in benzene metabolizing genes may modify benzene toxicity and should be taken into consideration during risk assessment evaluations.

Exposição ao benzeno em postos de revenda de combustíveis no Brasil: Rede de Vigilância em Saúde do Trabalhador (VISAT) / Exposure to benzene in gas stations in Brazil: occupational health surveillance (VISAT) network

O objetivo deste artigo é apresentar a experiência da rede de vigilância da exposição ao benzeno em Postos de Revenda de Combustíveis, descrevendo seus componentes, desenvolvida no Sistema Único de Saúde. Relato e análise de experiência de vigilância e seus impactos à saúde dos trabalhadores de postos de combustíveis em seis estados do Brasil. Apresenta a perspectiva de ação operada pela circulação de informações, encontros nacionais, discussões de estratégias particulares e compartilhadas das experiências, metodologias e instrumentos comuns. São descritos procedimentos de inspeção, avaliações individuais e formação. Foram identificadas situações de risco e exposições ocupacionais e ambientais em 1.312 postos e 564 trabalhadores foram avaliados. Estavam expostos frentistas, chefes de pista e encarregados de medição, descarga e testes. As características integradas e complementares desta vigilância, articuladas às áreas ocupacional e ambiental, contemplam a intervenção a territórios ampliados e conectados em rede. A intervenção supera as fragmentações entre práticas individuais e coletivas e entre serviços e ensino, tornando-se um exemplo de ação para avaliação e redução do impacto à saúde em trabalhadores, pela articulação da ação sanitária, ambiental e de conexão intersetorial.

The scope of this article is to present the surveillance network's experience of exposure to benzene in gas stations, describing its components developed in the Unified Health System. It is a report and analysis of the experience of monitoring and its impact on the health of gas station workers in six Brazilian states. It presents the prospect of action, operated by the circulation of information, national meetings, discussions of specific strategies and shared experiences, methodologies and common tools. Inspection procedures, individual assessments and training are described. Risk situations and occupational and environmental exposure were identified in 1,311 gas stations and 564 workers were assessed. Forecourt attendants, superintendents and measuring, offloading and testing employees were all exposed. The integrated and complementary features of this surveillance, implemented in the occupational and environmental areas, suggest intervention in a broader and network-linked territory. The intervention would transcend fragmentation between individual and collective practices, services and education, becoming an example of action for assessment and mitigation of the impact on health workers, the articulation of action in health, the environment and intersectorial connection.

[Exposure to benzene in gas stations in Brazil: occupational health surveillance (VISAT) network]. / Exposição ao benzeno em postos de revenda de combustíveis no Brasil: rede de Vigilância em Saúde do Trabalhador (VISAT).

The scope of this article is to present the surveillance network's experience of exposure to benzene in gas stations, describing its components developed in the Unified Health System. It is a report and analysis of the experience of monitoring and its impact on the health of gas station workers in six Brazilian states. It presents the prospect of action, operated by the circulation of information, national meetings, discussions of specific strategies and shared experiences, methodologies and common tools. Inspection procedures, individual assessments and training are described. Risk situations and occupational and environmental exposure were identified in 1,311 gas stations and 564 workers were assessed. Forecourt attendants, superintendents and measuring, offloading and testing employees were all exposed. The integrated and complementary features of this surveillance, implemented in the occupational and environmental areas, suggest intervention in a broader and network-linked territory. The intervention would transcend fragmentation between individual and collective practices, services and education, becoming an example of action for assessment and mitigation of the impact on health workers, the articulation of action in health, the environment and intersectorial connection.

[Exposure to VOCs in furniture factories in two populations in northern Colombia]. / Exposición a COVs en fábricas de muebles de dos poblaciones del norte de Colombia.

OBJECTIVES: Assess the exposure to volatile organic compounds (VOCs)in furniture handicraft factories workers in two populations of Sucre (Sincelejo and Sampués), North of Colombia.Identify possible signs and/or symptoms related to exposure to these contaminants. METHODS: This was an analytical cross sectional study (2011), using a questionnaire. Study population consisted of 66 individuals, 41 exposed and 25 controls. Personal samples were collected for concentration quantifying of benzene, toluene, ethylbenzene and xylenes (both groups) and contrasting them with health effects possible attributed to these contaminants. RESULTS: The concentrations of benzene, toluene and m/p-xylene were higher in the exposed group (9.5 mg/m(3), 8.1 mg/m(3) and 12.1 mg/m(3))compared with the control group (0.2 mg/m(3), 0.3 mg/m(3) and 0.03 mg/m(3)). Muscular pain 82.9 % (PR=3.8; CI95%:1.2-11.8) and somnolence 65.9 % (PR=4.9; CI95%:1.7-14.7)were associated with a higher exposure.Factor such as mixtures of solvents (thinner) in the work and vehicles' traffic can contribute to these results. CONCLUSIONS: Several sources contribute to increases personal exposure of VOCs in furniture handicraft factories workers North of Colombia. Additionally, excessive use of these compounds may be generating adverse effects on the health of workers.

Exposure to indoor air pollutants (polycyclic aromatic hydrocarbons, toluene, benzene) in Mexican indigenous women.

UNLABELLED: Indoor air pollution is considered to be a serious public health issue in Mexico; therefore, more studies regarding this topic are necessary. In this context, we assessed exposure to polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds in: (i) women who use firewood combustion (indoor) for cooking and heating using traditional open fire; (ii) women who use firewood combustion (outdoor) for cooking and heating using traditional open fire; and (iii) women who use LP gas as the principal energy source. We studied 96 healthy women in San Luis Potosi, México. Urine samples were collected, and analyses of the following urinary exposure biomarkers were performed by high-performance liquid chromatography: 1-hydroxypyrene (1-OHP), trans, trans-muconic acid, and hippuric acid (HA). The highest levels of 1-OHP, trans, trans-muconic acid, and HA were found in communities where women were exposed to indoor biomass combustion smoke (or products; geometric mean ± s.d., 3.98 ± 5.10 µmol/mol creatinine; 4.81 ± 9.60 µg/l 1-OHP; 0.87 ± 1.78 mg/g creatinine for trans, trans-muconic acid; and 1.14 ± 0.91 g/g creatinine for HA). Our findings indicate higher exposure levels to all urinary exposure biomarkers studied in women who use indoor firewood combustion for cooking and heating (using traditional open fire). PRACTICAL IMPLICATIONS: High mean levels of 1-hydroxypyrene, t,t-muconic acid, and hippuric acid were found in women who use firewood combustion (indoor) for cooking and heating using traditional open fire and taking into account that millions of women and children in Mexico are living in scenarios similar to those studied in this report, the assessment of health effects in women and children exposed to polycyclic aromatic hydrocarbons and volatile organic compounds is urgently needed. Moreover, it is immediately necessary an intervention program to reduce exposure.

Saúde do trabalhador e a sustentabilidade do desenvolvimento humano local: ensaios em Pernambuco / Occupational Health and sustainability of local human development: Essays in Pernambuco

Desde meados da década de 80 diversas experiências locais de internalização da saúde do trabalhador na rede pública de atenção à saúde foram realizadas no Brasil. A saúde como qualidade de vida humana deve estar no centro das politicas para o desenvolvimento. Mas este é um desafio que se coloca para a consolidação do SUS. Este livro tenta trazer o tema para os contextos locais, onde se materializam os processos de trabalho e oferecer aos profissionais de saúde, e outros interessados, alguns cenários e metodologias para auxiliar a organização da proteção e da promoção da saúde, nos contextos de desenvolvimento humano, como dever do Estado.

Riesgo infantil por exposición a carcinógenos en un área de alto tránsito vehicular / Child risk exposure to carcinogens in a high traffic area

La contaminación del aire es una amenaza aguda, acumulativa y crónica para la salud y el ambiente. Las personas están expuestas a contaminantes de aire en exteriores e interiores. Las exposiciones a los mismos puede generar o agravar afecciones respiratorias, cardíacas y otras. La presente experiencia nace como la necesidad de conocer la calidad del aire en áreas de alto tránsito vehicular, con potencial riesgo para la salud de la población infantil. Experiencia que se desarrolla desde la gestión de la Dirección de Salud Ambiental, con una visión epidemiológica, con la participación de Centros de Investigación-Universidades Nacionales y recursos municipales.Sobresale en esta investigación la caracterización de escenarios de riesgo por los valores alto de benceno; con su correspondiente índice de peligro, según peso corporal del niño. También por el alto porcentaje de emisiones vehicular de material particulado. Se ha detectado la presencia en el 21 % de las muestras benzo[a]pireno, asociados con las partículas finas y se ha encontrado mayor valor de mutagenicidad (ensayo de Ames), en una de las zonas bajo estudio. Detección de tóxicos críticosque estarían presentes, durante la ventana de vulnerabilidad crítica del desarrollo del niño, llevando a intensificar las medidas correctivas y los estudios en la población vulnerable.

Phenotype analysis of lymphocytes of workers with chronic benzene poisoning.

Lifetime exposure to benzene is associated to a variety of blood disorders, and except for the risk of cancer, almost nothing is known concerning health impairment in individuals who are no longer exposed. In Brazil, this exposure is one of the serious problems in workplaces, and many workers have been laid off their jobs due to this intoxication, particularly in the State of Bahia, the largest producer of benzene in Latin America, which is the area of this study. From a larger study to describe health effects and genetic polymorphisms among workers with chronic benzene poisoning (CBP), this previous specific investigation analyzes the association between CBP and the pattern of sub-populations of lymphocytes. The study was performed with a CBP group (n=24) and a control group with other occupational diseases (n=24); both were selected at the Workers Health Study Center in the State of Bahia, Brazil. Clinical and epidemiologic variables were collected from medical records and from a detailed questionnaire. The average age was similar in the two groups (51.1 and 50.7, respectively). Analyzing the mean proportions of the sub-populations of lymphocytes, statistically significant differences were found for T cytotoxic cells (TCD8) (27.9; 19.4; p=0.002) and T helper memory cell (CD4CD45RO) (31.2; 37.0; p=0.015), respectively, for the CBP group and control group. These results should be viewed with caution because of the small sample size, but they strengthen a previous impression that workers exposed to benzene have their immune system impaired, even in the long term, which may contribute to some disorders and carcinogenesis process. These workers must be strictly followed up in a medical surveillance program. Although this problem has been known for a long time, this is the first attempt to study these specific effects in Brazil.

Non-Hodgkin's lymphomas and organic solvents.

Organic solvents have been suggested as a possible risk factor for non-Hodgkin's lymphomas (NHL). We studied 109 NHL incident cases and 276 controls with other cancers (1990/1996) in the city of Salvador, Brazil. Occupational exposure to organic solvents was evaluated through standardized questionnaires and defined by industrial hygienists, taking into account individuals' lifetime history. An association between occupational exposure to organic solvents and NHL was observed, OR = 1.67 (95% CI, 0.97 to 2.87), especially among individuals less than 64 years, OR = 1.91 (95% CI, 0.99 to 3.67), and among those who used domestic insecticides, OR = 2.24 (95% CI, 1.01 to 3.97). Odds ratios were similar for nodal and diffuse NHL. These results suggest that organic solvents may contribute to the causation of NHL, especially among young individuals, and that synergism may play a role in the process of lymphomagenesis.

[Liver function of workers occupationally exposed to mixed organic solvents in a petrochemical industry]. / Función hepática de trabajadores ocupacionalmente expuestos a solventes orgánicos mixtos en una Industria Petroquímica.

A descriptive and cross sectional study was conducted to determine whether hepatic function changes in workers occupationally exposed to a mixture of organic solvents, were due to the exposure or confusing factors. A non random sample of 77 workers, operators and supervisors of the Olefin Plant I and II of a petrochemical industry in Maracaibo, Venezuela, was used. Their mean age was 29 +/- 7 years, and had at least one year of exposure to the solvents. This sample was compared with a group of employees of the administrative offices or control panel workers, with a mean age of 36 +/- 8 year and with similar anthropometric characteristics. Workers with a known history of liver disease, blood transfusions and diabetes mellitus were excluded of the study. In addition to a complete occupational disease medical history and a physical examination, serum samples were obtained to determine the activity of the aspartato aminotransferase (AST), alanin aminotransferase (ALT), gamma glutamiltransferase (GGT), alkaline phosphatase (AF), the concentration of the total bile acids (BAS), the surface antigen of hepatitis B(HbsAg) and the hepatitis A virus antibodies: AntiHAV-IgG and the AntiHAV-IgM. An urine sample was taken and analyzed by standard methodology to determine urinary phenols. The air concentrations of benzene, ethylbenzene, toluene and xylene were analyzed by gas chromathography. The serum activities of the liver enzymes, the concentration of bile acids and urinary phenols were not influenced by the exposure to the solvents. The increase of the activity of GGT was associated with obesity and alcohol consumption. The antibodies of the surface antigen of hepatitis A-IgM were normal in both groups and the antibodies for the antigen of hepatitis A-IgG presented a prevalence of 6% in the exposed group and 9% in the non exposed not being associated with liver abnormalities. The individual air concentrations of the solvents were below the environmentally permissible concentrations, except one sample of benzene (1, 14 ppm) that was over the allowed limit. The total maximum concentration of the mixture of organic solvents, resulting of the sum of fractions of each organic solvent, was within the allowed limits. In conclusion, obesity and alcohol consumption, and not the occupational factors, seem to be responsible for the alteration in GGT in workers of these Olefin Plants.